Originally posted by Firefly218
On average, elves are just as skilled as men, if not more. Therefore, single and impactful human fighters like Aragorn won't have as big of an impact in a war of billions. Judging solely based on sheer physical and technological advantages, I would give the elves the edge.
The biggest not-talked about issues here are leadership, envinronment, feasibility of such large numbers to wage a war and inclusion of magic. Battles are won by tactical and strategic positioning, environmental factors, psychological factors, technology, etc. Man for man, elves are far superior to humans. First Age elves especially so (as has been noted, first two ages, Elves stomp Humans horribly). However, millions of humans can be easily scared. They can easily lose heart for battle, after seeing thousands of humans die. They can be disorganized, become selfish (humans are arguably more selfish and less socially self-identifying than elves who have ridiculously strong vows and personal bonds) and they have inferior equipment and training. A large chunk of humans are just mooks and badly trained ones at that. For every well trained militia or general or archer, there's hundreds if not thousands of everyday people who are millers, barkeeps, fletchers, etc. These are not going to be of consequence unless they are stocked in the front row for slaughter, to be a meat barrier to the proper soldiers in the back.
In a somewhat sensible scenario, these untrained humans would hold the back lines and flee or be routed with ease. The actual fraction of humanity that is able to fight (which would include First Age clans, Second Age Numenorians) would put up a hell of a fight. Many many elves would die. But elves could possibly take the day if leadership is strong, they stick together, utilize their magic and archery and superior tactics intelligently. Top level elves have ridiculous powers that only the Numenorians could attempt to match. How long would humanity stand its ground when you have elf-lords butchering whole groups of men with concentrated arrow fire, ice-cold razor-sharp weaponry that is enchanted, and mystical powers one cannot understand?
In a straight up brawl, elves could not hold their ground. With some prep, a clear line of command, and proper usage of their strengths, it could turn into a rout.